Magnetic field induced phenomena in UIrGe in fields applied along b axis

TL;DR

This study investigates the magnetic field-induced phenomena in UIrGe, revealing a complex metamagnetic transition with temperature-dependent order and anomalies linked to antiferromagnetic correlations, using magnetization and heat capacity measurements.

Contribution

It provides new insights into the field-induced magnetic transitions and anomalies in UIrGe, highlighting the temperature-dependent nature of the metamagnetic transition and associated phenomena.

Findings

First-order transition below 13 K; second-order above 13 K.

Anomalous S-shape in magnetization isotherms at T > 13 K.

Correlation of anomalies with antiferromagnetic correlations.

Abstract

The metamagnetic transition between the antiferromagnetic and paramagnetic state in UIrGe has been studied at various temperatures by magnetization, heat capacity and magnetocaloric-effect measurements on a single crystal in static and pulsed magnetic fields applied along the orthorhombic b-axis. A first-order transition is observed at temperatures below 13 K and a second-order one at higher temperatures up to the N\'eel temperature (TN = 16.5 K). The first-order transition is accompanied by a dramatic increase of the Sommerfeld coefficient. Magnetization measurements extended to the paramagnetic range revealed an anomalous S-shape (inflection point at a magnetic field Hm) in magnetization isotherms at temperatures above 13 K and a temperature dependence of susceptibility with a maximum at Tmax well above TN. The lines representing the temperature-induced evolution of Hm and field-induced evolution of Tmax, respectively, are bound for the point in the magnetic phase diagram at which the order of metamagnetic transition changes. A tentative scenario explaining these anomalies by antiferromagnetic correlations or short-range order in the paramagnetic state is discussed.